The proposed changes include adding black triangles to the labelling of new medicines or vaccines with provisional registration, suspected safety concerns or limited use internationally.

“Rare adverse events may not be detected in clinical trials, and since there is variation between individuals in the way they respond or react to medicines, there is the potential for previously unknown adverse events to occur at any time,” the consultation paper says.

The authorities say that while all medicines registered in Australia are well studied, some adverse events cannot be predicted in clinical trials.

Europe already uses a black triangle system to explain the safe and effective use of drugs.

The TGA wants to use the symbol on documents for medical professionals and consumers, including advertising, promotional and education materials, the Australian Medicines Handbook, and prescribing and dispensing software.

As well as the black triangle idea, the TGA is looking to reformat product documentation so that important prescribing information is more accessible.